Process for protecting a substrate with an n{11 substituted aminoarylsulfonamide intumescent agent

ABSTRACT

Intumescent compositions of the invention comprise certain N4thiazolyl, isothiazolyl, oxazolyl, and isoxazolyl aminoarylsulfonamides, such as N4-2-thiazolylsulfanilamide, N4-5isothiazolylsulfanilamide, N4-2-oxazolylsulfanilamide, N4-5isoxazolylsulfanilamide, and derivatives thereof. The intumescent agents may be employed in conjunction with additives conventionally used in intumescent compositions. For use in protecting substrates from heat and fire, the intumescent compositions may be applied to the substrates in any suitable manner, such as by electrodeposition, spraying onto an adhesive substrate, or application of a coating composition comprising the intumescent agent.

ma mal 51 i PW t :2 United States Roth [ PROCESS FOR PROTECTING A SUBSTRATE WITH AN N -SUBSTITUTED AMINOARYLSULFONAMIDE INTUMESCENT AGENT [75] Inventor: Shirley H. Roth, Highland Park, NJ.

[73] Assignee: Cities Service Company, New York,

[22] Filed: Feb. 28, 1972 [21] Appl. No.: 230,133

52 U.s. Cl. 117/136, 106/15 F? [51] Int. Cl. C09d 5/18, C09k 3/28 [58] Field of Search 117/136; 252/8.1; Y 106/15 FP; 260/239.95

[56] References Cited UNITED STATES PATENTS 2,426,313 8/1947 Ludwig et a]. 260/239.95 X 3,535,130 10/1970 Webb 117/136 X 3,663,464 5/1972 Sawko... 117/136 X 3,707,554 12/1972 Hardy 117/136 X OTHER PUBLICATIONS Chem. Abs., No. 1772-1, Vol. 35 (1941).

Dec. 4, 1973 Chem. Abs., No. 14611e, Vol. 50 (1956).

Primary Examiner-William D. Martin Assistant Examinerl-1arry J. Gwinnell Attorney-Richard S. Strickler et a].

[5 7 ABSTRACT lntumescent compositions of the invention comprise certain N-thiazolyl isothiazolyl, oxazolyl, and isoxazolyl aminoarylsulforfamides, such as N -2- thiazolylsulfanilamide, N-5-isothiazolylsulfanilamide, N -2-oxazoly1sulfani1amide, N -5-isoxazolylsulfanilamide, and derivatives thereof. The intumescent agents may be employed in conjunction with additives conventionally used in intumescent compositions. For use in protecting substrates from heat and fire, the .intumescent compositions may be applied to the substrates in any suitable manner, such as by electrodeposition, spraying onto an adhesive substrate, or application of a coating composition comprising the intumescent agent.

5 Claims, N0 Drawings PROCESS FOR PROTECTING A SUBSTRATE WITH AN N SUBSTITUTED AMINOARYLSULFONAMIDE INTUMESCENT AGENT BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to intumescent compositions and more particularly relates to such compositions containing a one-component intumescent agent.

2. Description of the Prior Art It is known that a substrate may be protected from heat and fire by the application of an intumescent composition. lntumescent compositions of the prior art usually contain an intumescent agent having at least three components; i.e., a carbonific, a spumific, and a catalyst; and they are typically characterized by the disadvantages of high cost, low spreading rate, relatively poor efficiency, poor water resistance, and poor weather-ability.

As disclosed in U. S. Pat. No. 3,535,130, it has already been discovered that a one-component intumescent agent has advantages over multicomponent intumescent agents. However, the intumescentagents of the patent have poor adherence to substrates and have an undesirable degree of moisture sensitivity.

SUMMARY OF THE INVENTION An object of this invention is to provide a novel class of one-component intumescent agents.

Another object is to provide such intumescent agents having good efficiency and a low level of moisture sensitivity.

These and other objects are attained by using as intumescent agents compounds corresponding to the formula:

wherein Ar is a divalent aromatic residue, R is a thiazolyl, substituted thiazolyl, isothiazolyl, substituted isothiazolyl, oxazolyl, substituted oxazolyl, isoxazolyl, or substituted isoxazolyl radical, and R is hydrogen, hydrocarbon, substituted hydrocarbon, or acyl.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The intumescent agents of the invention may be any compounds corresponding to the above formula. HOwever, they are preferably compounds wherein Ar is a divalent aromatic residue derived from benzene or naphthalene or an alkyl, haloalkyl, alkoxy, haloalkoxy,

halo, hydroxy, carboxy, amino, amido, or nitro derivative thereof. When the aromatic ring bearsorganic substituents, it is usually preferred that these substituents bromobenzenesulfonamide,

keto, carboxy, hydroxy, amino, amido, sulfonamido,

; nitro, C -C5 alkyl, C -C chloroalkyl, C -C bromoalkyl,

C -C hydroxyalkyl, C -C carboxyalkyl, phenyl, and benzo derivatives, but compounds containing other substituted thiazolyl, isothiazolyl, oxazolyl, or isoxazolyl radicals are also utilizable. When R is such a substituted radical, the nitrogen of the ar-amino group may be attached directly to the thiazole, isothiazole, oxazole, or isoxazole ring, or it may be attached to the ring through the substituent.

As indicated above, R may be hydrogen or a hydrocarbon, substituted hydrocarbon, or acyl radical, preferably hydrogen or a C -C alkyl, phenyl, aminophenyl, sulfonamidophenyl, nitrophenyl, or acetyl radical.

Exemplary of the intumescent agents of the invention are N -2-thiazolylsulfanilamide, N-3-isothiazolylsulfanilamide, N -2-oxazolylsulfanilamide, N"-3-isoxazolylsulfanilamide, 4-(2-thiazolyl)amino-3- chlorobenzenesulfonamide, 2-(2-thiazolyl)amino-4- 4-(2-thiazolyl)amino-2- 3-(2-thiazolyl)amino-4- 4-( 2- 4-(2- ethylbenzenesulfonamide, chloromethylbenzenesulfonamide, thiazolyl)amino-2-butoxybenzenesulfonamide,

'thiazolyl)amino-3-chloromethoxybenzenesulfonamide,

4-(2-thiazolyl)amino-3-hydroxybenzenesulfonamide, 4-(2-thiazolyl)amino-3-carboxybenzenesulfonamide, 4-(2-thiazolyl)amino-3-aminobenzenesulfonamide, 4- (Z-thiazolyl)-amino-2-acetamidobenzenesulfonamide, 2-(Z-thiazolyl)-amino-4-nitrobenzenesulfonamide, N- (3-methyl-2-thiazolidyl)sulfanilamide, N-(4-chloro-2- thiazolyl-)sulfanilamide, N (4-bromo-2- thiazolyl)sulfanilamide, N -(4-ethoxy-2- thiazolyl)sulfanilamide, N (4-oxy-2-thiazolyl)- sulfanilamide, N-(5-methylketo-2- thiazolyl)sulfanilamide, N-(4-carboxy-2- thiazolyl)sulfanilamide, N -(4-hydroxy-2- thiazolyl)sulfanilamide, N -(2-amino-4- thiazolyl)sulfanilamide, N-(5--methylamido-2-benzothiazolyl)sulfanilamide, N-(6-sulfonamido-2-benzothiazolyl)sulfanilamide, N-(6-nitro-2-benzothia2olyl)- sulfanilamide, N -(4-methyl-2-thiazolyl)sulfanilamide, N-(5-chloromethyl-Z-thiazolyl)-sulfanilamide, N-'(5- bromomethyl-Z-thiazolyl)sulfanilamide, N-(5- hydroxyethyl-4-methyl-2-thiazolyl)sulfanilamide, N- (5-ethylcarboXy-4-methyl-2-thiazolyl)sulfanilamide, N-(4-phenyl-2-thiazolyl)sulfanilamide, N -2-benzothiazolylsulfanilamide, N -ethyl-N -2- thiazolylsulfanilamide, N-(4-aminophenyl)-N -2- thiazolylsulfanilamide, N-(4-sulfonamidophenyl)-N"- 2-thiazolylsulfanilamide, N-(4-nitrophenyl)-N -2- thiazolylsulfanilamide, N -acetyl-N -2- thiazolylsulfanilamide, the corresponding naphthalene compounds, the corresponding derivatives of isothiazole, oxazole, and isoxazole, etc. When not readily available, these compounds may be prepared by known techniques.

For use in protecting a substrate from heat and fire, the intumescent agents of the invention may be applied in any suitable manner, e.g., electrodeposition, spraying of powdered intumescent agent onto an adhesive substrate, etc. However, it is usually preferred to compound the intumescent agent with a binder, e.g., nitrocellulose, and optionally also with one or more of the other ingredients conventionally used in intumescent compositions, e.g., stabilizers, dispersing agents, pigments, driers, biocides, anti-foamers, thickeners, protective colloids, fillers, blowing agents, etc.; disperse the composition in a suitable liquid medium, e.g., water or a solvent or solvent mixture; and apply the coating composition thus formed to the substrate to be protected. As is the case with conventional intumescent coating compositions, it is frequently convenient to apply these coating compositions in the form ofa paint having a solids content of about 10-70 percent by weight and an intumescent agent/binder weight ratio of about 0.075l4/l to deposit a coating having a dry thickness of about 0.00l-O.75 inch.

The intumescent agents of the invention are efficient, have low moisture sensitivity, and intumesce to form foams having good volume, cell structure, and adherence to substrates, such as wood, metal, and plastics. They are also useful as flame retardants in normally flammable compositions.

The following example is given to illustrate the invention and is not intended as a limitation thereof.

EXAMPLE 1 Place one gram of N-Z-thiazolylsulfanilamide, in an aluminum pan and flame it with a propane torch. The compound intumesces to form an excellent volume of foam having a good cell structure.

Similar results are also observed when the other intumescent agents mentioned in the specification are substituted for the intumescent agent of the Example.

It is obvious that many variations may be made in the products and processes set forth above without departing from the spirit and scope of this invention.

What is claimed is:

l. A process for protecting a substrate from heat and fire which comprises applying thereto an intumescent composition comprising as the intumescent agent a compound corresponding to the formula:

wherein Ar is a divalent aromatic residue, R is a thiazolyl, substituted thiazolyl, isothiazolyl, substituted isothiazolyl, oxazolyl, substituted oxazolyl, isoxazolyl, or substituted isoxazolyl radical and R is hydrogen, hydrocarbon, substituted hydrocarbon, or acyl.

2. The process of claim 1 wherein Ar is a divalent aromatic residue derived from benzene or naphthalene or an alkyl, haloalkyl, alkoxy, haloalkoxy, halo, hydroxy, carboxy, amino, amido, or nitro derivative thereof.

3. The process of claim ll wherein R is a thiazolyl radical or an amino, alkyl, haloalkyl, hydroxyalkyl, carboxyalkyl, phenyl or benzo derivative thereof.

4. The process of claim ll wherein R is hydrogen.

5. The process of claim 1 wherein the intumescent agent is N -2-thiazolylsulfanilamide. 

2. The process of claim 1 wherein Ar is a divalent aromatic residue derived from benzene or naphthalene or an alkyl, haloalkyl, alkoxy, haloalkoxy, halo, hydroxy, carboxy, amino, amido, or nitro derivative thereof.
 3. The process of claim 1 wherein R is a thiazolyl radical or an amino, alkyl, haloalkyl, hydroxyalkyl, carboxyalkyl, phenyl or benzo derivative thereof.
 4. The process of claim 1 wherein R'' is hydrogen.
 5. The process of claim 1 wherein the intumescent agent is N4-2-thiazolylsulfanilamide. 